Conductors carrying high frequency signals and currents are subject to interference and crosstalk when placed in close proximity to other conductors carrying high frequency signals and currents. This interference and crosstalk can result in signal degradation and errors in signal reception. Coaxial and shielded cables are available to carry signals from a transmission point to a reception point, and reduce the likelihood that the signal carried in one shielded or coaxial cable will interfere with the signal carried by another shielded or coaxial cable in close proximity. However, at points of connection, the shielding is often lost, thereby allowing interference and crosstalk between signals. The use of individual shielded wires and cables is not desirable at points of connections due to the need for making a large number of connections in a very small space. In these circumstances, two-part high speed electrical connectors containing multiple shielded transmission lines are used. Specification IEC 61076-4-101 from the International Electrotechnical Commission sets out parameters for 2 mm, two-part connectors for use with printed circuit boards.
As users modify and upgrade systems to achieve improved performance, problems related to backward compatibility arise between, for example, CompactPCI or FutureBus connectors and modern high speed shielded connectors. This means that users wishing to upgrade their system performance by changing to a shielded connector system must upgrade both connector elements (header and socket components) and perhaps additionally change the overall packaging of their system. An electrical connector that provides an increase in performance, while still permitting backwards compatibility with, for example, CompactPCI or FutureBus connectors is desirable.